Reduce update frequency from RazorWorkspaceListener

[ryzngard]

This is the start of making it so the information sent over the named pipe is less noisy. The aim is to detect if any changes need to be synchronized to razor. It still calculates and serializes the full project information; the aim is to reduce that in a later PR.

[DustinCampbell]

I took a pass through and added some comments. Beyond the minor feedback, I strongly suggest not relying on GetHashCode(). Instead, use our Checksum infrastructure to produce stronger identity for the cache.

[DustinCampbell]

This won't do what you want. Instead, it'll likely return true almost every time. RazorProjectInfoHelpers.GetDocumts() returns a new ImmutableArray<DocumentSnapshotHandle> each time it's called, and ImmutableArray<T>.GetHashCode() isn't computed from the contents; it just passes the reference to the underlying array.

To address this, please use Microsoft.AspNetCore.Razor.Utilities.Checksum and build up a checksum.

[davidwengier]

I didn't look too closely at anything after my last comment, because it seemed like Dustin covered it. Definitely +1 to the GetHashCode() usage, it definitely reads as potentially incorrect (eg, even though RazorConfiguration defines an override, is it handling its Extensions property correctly??). If it isn't, then comments confirming that would be appreciated.

[davidwengier]

Given the null check, bool Try...(out, out) could also be appropriate

[ryzngard]

Converting to draft while I think on this more

[ryzngard]

Replaced with #10813